Mathematical mum

Come on kid time to go shopping:said mum,nooo groaned the kids,come on kids let's go said mathematical mum.Okay Adam if I had 6  juices for your lunches how many would be left by friday:said mum, none so we need 5 packs so there would be 3 more left over for monday:said Adam.Great Adam,Bob if the bananas are 3 dollars for 5 bananas how many bananas would we have for 15 dollars,mum that's to hard:said Bob.Just do it:said mum.. Okay we would have 25 bananas:said Bob.Amazing now go get the bananas:said mum.Mark if the cheese are $5:20 cents how much will it cost for 3 cheeses:said mum.What that's just too hard why can’t Adam or Bob do that.no:said mum you need to do it they all ready got their turn so now it’s your turn.Okay,hmm if we get 3 cheese for $5:20 how much would it be.For 2 cheese it will cost $10:40 so $10:40 + $5:20 = $15:60.Good Mark:said mum now we can go home. Yay!! Said the kids we can finally go home.